Chapter 1 : SystemC Overview

1. Chapter 1 : SystemC Overview

2. What is SystemC • Systemc is a modeling platform • A set C++ class library to add hardware modeling constructs • Simulation kernel • Supports different levels of abstraction • Untimed Functional Model • Transaction Level Model • Bus Function Model

3. Why we need systemc • The increasingly shortened time to market requirements • Verify the design in early time • The growing complexity • Integration of devise devices

4. SystemC Heritage ref : SOCLab 03_SOC_Design_Flow.pdf, 2004 spring, NCTU

5. SystemC Design Flow

6. Using software to simulate hardware behavior • Extensions • Parallel execution • Clock • Module concept • Interconnection

7. Example – half adder #include “systemc.h” SC_MODULE(half_adder) { sc_in<bool>a, b; sc_out<bool>sum, carry; void proc_half_adder(); SC_CTOR(half_adder) { SC_METHOD (proc_half_adder); sensitive << a << b; } }; void half_adder::proc_half_adder() { sum = a ^ b; carry = a & b; }

8. Module --- Basic Block • Verilog module module_name(input/output declaration) variable declaration computation block endmodule • SystemC SC_MODULE (module_name) { input/output declaration internal variable constructor (computation block) };

9. Input/output Declaration • Verilog • Input : input var1, …; • Output : output var2, …; • Type • SystemC • input : sc_in<type> var1, …; • Output : sc_out<type>var2, …; • Type • C++ primitive type : int, float, char, ... • hardware type : sc_int, sc_uint, ... • user defined type

10. Computation Block • Verilog • Event trigger : always@(a or b or c) • Edge trigger : always@(posedge clk) • SystemC SC_CTOR (module_name) { SC_METHOD (function name); sensitive << a << b << c; … } C++ constructor Computation function name Sensitivity list

11. Describing Hierarchy #include “half_adder.h” SC_MODULE (full_adder) { sc_in<bool>a, b, carry_in; sc_out<bool>sum, carry_out; sc_signal<bool>c1, s2, c2; void proc_or(); half_adder ha1(“ha1”), ha2(“ha2”); SC_CTOR(full_adder) { ha1.a(a); //by name connection ha1.b(b); ha1.sum(s1); ha1.carry(c1); h2(s1, carry_in, sum c2) //by position connection SC_METHOD (proc_or); seneitive << c1 << c2; } };

12. Main --- Top Module #Include “full_adder.h” #Include “pattern_gen.h” #include “monitor.h” int sc_main(int argc, char* argv[]) { sc_signal<booL> t_a, t_b, t_cin, t_sum, t_cout; full_adder f1(“Fulladder”); //connect using positional association f1 << t_a << t_b << t_cin << t_sum << t_cout; pattern_gen pg_ptr = new pattern_gen(“Genartion”); //connection using named association pg_ptr->d_a(t_a); pg_ptr->d_b(t_b); (*pg_ptr->d_cin(t_cin); monitor mol(“Monitor”); mo1 << t_a << t_b << t_cin << t_sum << t_cout; sc_start(100, SC_NS); return 0; }

13. SystemC Installation • Download • http://twins.ee.nctu.edu.tw/courses/soc_sys_overview_04fall/lab/systemc-2.0.1.tgz • http://www.systemc.org • Decompress data to /path/to/destination • C:\temp\ systemc-2.0.1\ • Open project file • C:\temp\systemc-2.0.1\msvc60\systemc\systemc.dsw • Build • Build->Build systemclib (F7)

14. Project compilation • Example • http://twins.ee.nctu.edu.tw/courses/soc_sys_overview_04fall/lab/systemc_ex01.rar • Decompression • C:\temp • Create new project • File->New->Project->win32 Console application -> empty project • Add existed files • Project->Add to Project -> Files • main.c module.c module.h • Building argument and dependency • C++ runtime type indentification • Include path • Link path and libaray